Outside plant enclosures for electrically powered equipment such as communications equipment need to be maintained within specified temperature ranges to prevent equipment failure from, e.g., overheating. Such enclosures are often air conditioned to prevent overheating. The enclosures are often insulated from the external environment, particularly in hot climates or in hot seasons, to reduce overall demand on the air conditioning system and to reduce the cycling of the air conditioning system between ON and OFF states. Temperature cycling is undesirable because it can accelerate the failure of electronic components.
Insulation of such enclosures has some disadvantages, however. For example, in the event that the air conditioning system is shut down or there is an outage of utility-provided power, the interior of the enclosure may rise to temperatures much greater than the external temperature. As a consequence, equipment is more likely to overheat and fail.
Thus, there is a need for a new thermal management system which can suppress cycling of the interior temperature of the enclosure and also suppress overheating when the air conditioning system is not operating.